Hi guys I am now back from Afghanistan and after all the problems I had with my first Range Rover, guess what? I bought another one!! A 2.5 diesel. Now I have a new problem, On a long drive today, I pulled into the service station and as I pressed my foot on the clutch the engine dropped its revs and it died.

I then bumped it as I was still rolling and it ran again. As I stopped, the engine died again and there was a light on the dash. I have never noticed this light before but it looks like an injector. It came on and went out again when it started after about 10 - 15 seconds cranking the engine over. Any ideas guys? I was thinking the fuel pump?! after driving it again for a bit, it seemed ok again but was still slow to start while cranking. If anyone knows or have had this before please help! Also if you know what it is, do you know where I can get the part? Thank you.........

It's telling you it is fuel related and hard to diagnose without T4.

It could be the fuel quantity sensor failing, or the fuel temperature sensor.

These is a trick to test the fuel temp sensor involving cooling the pump with cold water via a hose pipe. If it starts immediately after cooling the injector pump, then it is obviously the fuel temp sensor. Never performed the test myself (T4 gives me most clues) so someone else needs to fill in the details.

The trick with the cold water on the pump is to cool the pump, not the temp sensor. You can do this trick with any old mechanical diesel pump. All it does is cause the various parts of the pump to contract and therefore close up the tolerances and clearances. This gives you more fuel (and/or pressure) and therefore easier starting. It's why a lot of older and high mileage diesels always start easier from cold than they do when they're hot. The water temperature sensor is the main component for influencing how much fuel is delivered, hence the 'Hot Start Fixes' which bypass this sensor and fool the ECU into thinking it has a cold engine therebye giving it more fuel. The fuel temp sensor has some effect but very very little compared to the water temp sensor. It's noted in Rave that, if the fuel temp siensor fails, the ECU substitutes a value of 60 degs C ''and only slight effects on fueling may be noticed'' (quote from Rave). It really on works on temperature extremes.

The fuel quantity sensor in the pump will illuminate the injection warning light though as WSLR says if it fails or the signals from it are corrupted. I think the ECU also compares this signal with that from Nr4 injector and if these don't match, it will illuminate the warning light as well. (Nr4 injector has a lift feedback signal to the ECU, all the other 5 are just straight injectors).

I believe the fuel quantity sensor is part of the pump and is not a service part.

Another injector pump is required I believe - Is that right?

I'd go for replacing the crank sensor first.
Its the cheapest of all the sensors and if its not required will sell straight away on ebay for most of what you paid.

Your problem sounds a bit like the one where the engine cuts out on the over run. Common enough fault. With mine it was a combination of an intermittently faulty no.4 sensor with a dead crank sensor.
A bit like Derek says above, the Bosch EDC uses different sensors to check each other for fueling values. It takes the revs from the crank sensor and uses the no.4 injector as a check. However, on the over run the EDC actually cuts fuel flow to zero (so no signal from no.4 needle lift sensor) and then when it recieves a demand from the throttle sensor again it checks the revs but if the crank sensor is showing no revs it won't re-send fuel and so stalls. It won't restart until fuel gets to the no.4 sensor again on hot cranking settings.

Mine was doing it again lately when I'd cancel cruise control, solved problem temporarily by having foot on throttle before canceling cruise with left foot. Oh Yeah, that reminds me, if you buy the crank sensor and you don't need it, I'll buy it off you.

Thats putting my money where my mouth is

A better explanation SpudH. Cheers.